class_docstr: RNG provider that derives new RNGs from the key
code: def __init__(self, seed):
      self.seed = seed
  
file_path: lkpy/lenskit/util/random.py
imports: import numpy
  import seedbank
label_desc: Use image node_id 1 to create a new DerivingRNG object  with example: obj = DerivingRNG(seed)